What is called "pure Han"? People from State of Wu, State of Yue and State of Chu were not "Zhongyuan ren". Even ancient people from Shangdong were known as Dongyi. Han-Chinese was formed by the combination of many races after the Han Dynasty. Therefore, Cantonese are indeed Han-Chinese.

Why should we separate the north and south? We are in one Chinese family. Those who suggested the separation between the north and south are either foreigners or unfilial descendants of Chinese.

By the way Dongyi is closer to Bai Yue than Xiongnu, somewhere said that Xia Lord Yu's ancestry is also non-Huangdi tribe.
Yan-Di's totem is the same as Chi-You's (both are ox).
However some crazy untrained people claiming as genetists say Northerner is closer genetically to Mongolian and very far away from Southerner thus disqualifying from being Shang (Dongyi) descendant.

However, Han dynasty is far from North to South, thus both should be Han people.